Field of the Invention
The invention relates to an optical lens and an electronic device, and more particularly, to an optical imaging lens and a mobile device.
Description of Related Art
In recent years, the popularity of mobile products such as mobile phones and digital cameras allowed the rigorous development of imaging module-related techniques, and the imaging module mainly contains elements such as an optical imaging lens, a module holder unit, and a sensor, and the thin and light developing trend of mobile phones and digital cameras also resulted in a greater demand of the compactness of the imaging module. With the advancement of the techniques of charge-coupled device (CCD) and complementary metal oxide semiconductor (CMOS) and reduction in size, the length of the optical imaging lens installed in the imaging module also needs to be correspondingly reduced. However, to prevent reduction in photographic effects and quality, when the length of the optical imaging lens is reduced, good optical performance still needs to be achieved. The most important feature of the optical aging lens is expectedly imaging quality and size.
Specifications of mobile products (such as mobile phones, cameras, tablet computers, personal digital assistants, and automotive video devices) are ever changing, and the key component thereof, the optical lens set, is also being more dynamically developed, and the application not only covers photography and video recording, but also includes, for instance, environmental monitoring and driving records recording, and with the advancement of image sensing techniques, consumer demand for, for instance, imaging quality is also increased. Therefore, the design of the optical lens set not only requires good imaging quality and smaller lens space, when driving in an environment of insufficient lighting, increase in the field of view and aperture size is also an important topic.
However, the optical imaging lens design cannot produce an optical imaging lens having both imaging quality and small size simply by reducing the ratio of, for instance, a lens having good imaging quality, and the design process involves material properties, and actual issues on the production line such as assembly yield also needs to be considered.
The technical difficulty of manufacturing a small lens is significantly greater than that of a traditional lens, and therefore how to manufacture an optical imaging lens satisfying consumer electronic product requirements and continuing to increase the imaging quality thereof have always been highly desired goals of production, government, and academia in the field.
Moreover, in terms of a three-piece lens structure, in a conventional optical imaging lens, the distance from the object-side surface of the first lens element to the image plane on the optical axis is large, which is counterproductive to the thinning of mobile phones and digital cameras.